Interrelationship Between Coxackievirus A16 Antigen And Innate Lymphoid Cells In Respiratory Tract Epithelia And Immunological Analysis Of Its Vaccine Development

Coxackievirus type A 16(CA16)is a member of Human enterovirus A species of the Enterovirus genus of Picornaviridae.CA16 and Enterovirus 71(EV71)are considered as the major pathogens of human hand-foot-mouth disease(HFMD).Currently,with the broad application of the EV71 inactivated vaccine,CA16 has undoubtedly become another major pathogen causing HFMD.Because of the unclear pathogenesis of CA16,the development of a CA16 vaccine has encountered numerous difficulties.Previous studies have reported that epithelial cells and associated immune cells in respiratory tract mucosa,especially innate lymphoid cells(ILCs),largely contributed to the activation of innate and adaptive immune responses during viral infection.It is still unknown that whether ILCs play a similar role in the immune response induced by CA16 infection.To reveal the role of ILCs during CA16 infection,we firstly determined the expression levels of many genes related to ILC activation in CA16-infected human tracheal epithelial cells(16HBE).The results showed the levelsof IFN-TNF family signaling genes were significantly up regulated.Similarly,the expression level of these genes also increased in CA16 antigen internalized mice respiratory tract epithelial cells(CP-M175).Furthermore,we used a formulated experimental CA16-inactivated vaccine to immunize the Balb/c mice through nasal route,and analyzed the relationship between ILCs and viral antigens in the respiratory mucosa.Both CA16 live virus and inactivated virus particles can induce upregulation of various molecules required for the activation of ILCs in vitro and in vivo.Moreover,the viral antigen was found to co-localize with ILC 1 and ILC3 but not with ILC2.In addition,we also observed the colocalization of CA16 antigen and CD 11 c+ DCs.Subsequently,we tested the anti-CA 16 neutralizing antibodies and CTL responses in mice of different immunization pathways.All the results suggested that mice immunized through nasal route with the formulated CA16 inactivated vaccine could induce an ideal antiviral immune response in vivo.In this study,the interrelationship between ILCs and CA16 antigen was firstly analyzed in human tracheal epithelial cells.Then we use the mucosal respiratory tracts of Balb/c mice immunized by a formulated experimental CA16 inactivated vaccine via the nasal route,and the immunity induced in the immunized animals was identified.The results observed herein provide a clue to design a CA16 inactivated vaccine based upon the infectious route of the virus.